March 28 (Bloomberg) -- Isagen SA, the operator of
Colombia’s largest hydropower plant, dropped the most in a month
after a court ordered the temporary suspension of a plan to sell
a majority stake in the company.

The shares fell 0.8 percent to 3,195 pesos at 12:39 p.m. in
Bogota after earlier plunging as much as 3.7 percent, the most
on an intraday basis since Feb. 10. The stock was the worst
performer on the benchmark Colombian Colcap index, which gained
0.4 percent.

The Council of State’s ruling spurred speculation that the
government may have to delay the auction of its 57.6 percent
stake in Isagen, which would be worth 5 trillion pesos ($2.5
billion) at the minimum price. The council said in a statement
that it based the decision on Isagen’s importance as the
country’s third-largest power generator, providing significant
dividends to the government.

“We’re establishing these measures as a way to avoid
irreparable loss that afterward wouldn’t be reversible,”
Magistrate Maria Claudia Rojas, the president of the Council of
State, said in a phone interview. “Realistically, I don’t think
we’ll have a decision in less than a month and a half, because
we’re going to have to ask for evidence for an in-depth study.”

The shares had climbed earlier today to 3,295 pesos, the
highest this year on a closing basis, after the government
released a list yesterday of potential buyers requesting
approval to bid in the auction.

Suitors on the list included Charlotte, North Carolina-based Duke Energy Corp., Tractebel Energia SA, and Bogota-based
Empresa de Energia de Bogota SA.

China Huadian Corp., Gas Natural SDG SA and Cia Energetica
de Minas Gerais in association with Empresas Publicas de
Medellin ESP are also seeking to be prequalified.

Bidders are scheduled to present sealed offers in a May 8
auction, according to the government statement.